Extending internal solid wall

We are considering reducing the opening between lounge and dining area. Against current trends, but we are opening the kitchen (immediately to the right of the photo) through to the dinning area. That is being done by removing the door and extending the opening. A non load bearing wall; plasterboard onto metal studs (probably irrelevant information).
Our thought is to extend the right hand side of the arch by a little over1 mtr, reinstating the curve. The property is 20 years old and a solid concrete and screed floor. The wall is load bearing and 158mm thick.
Considered 1) concrete blocks with dot and dab plasterboard. 2) Timber studs with plaster board 3) Metal studs with plasterboard.
Presumably the with of the wall would require options 2 and 3 to need 2 frames with a small gap in the middle, or could I do something with double thickness plasterboard for example?
Thanks again in advance for your opinions.

 

Many thanks Jord86. I stumbled across wall starters after I had posted my question and they do address concerns I had about connecting the new wall to the old. I'll go ahead and follow your advice re-option 1.

 

Just one last thing (I hope), will I be OK building this directly on top of the screed floor as they are lightweight blocks and non-load bearing.
Presumably the existing wall was built prior to the screed being laid. This was certainly the case with the partition wall I am opening up as there is timber set into the screed on top of which is the metal channel for the studs.

 

Thanks again Jord86